Air-pump.



No. 642,354. Patented lan. 30, |900.

- J. N. MGLEAN.

AIR PUMP.

(Application led Jan. 13, 1896.)

2 Shets--Sheet .L

(No Model.)

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ma uonms wetens no.. wwwrun. wxsnma'mn o Q No. 642,354. Patented Jan.30, i900.

J. N. MCLEAN..

'AIR PUMP.

y (Application filed Jan. 13, 1896.) (No Model.) 2 Sheets-Sheet 2.

WITNESSES:

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' "NITED STATES PATENT OFFICE.

JOHN N. MCLEAN, OF NEW YORK, N. Y.

AIR-PUMP.

SPECIFICATION forming part of Letters Patent No. 642,354, dated January30, 1906. Application mea January 113.1896. Samia. massi. (Nomad.)

To cir/ZZ whom t may concern.-

Be it known that I, JOHN N. MOLEAN, a citizen of the United States, anda resident of New York, in the county and State of New York, haveinvented certain new and useful Improvements in Air-Pumps, of which the.fola lowing is a speciiication.

My invention relates to air-pumps for forcing or compressing air orother elastic iiuids and of the class suitable for hand operation.

The objects of myimprovements are, first, a construction that is neat,light, contained in small space, and easily portable; second, to providean actuating mechanism in which is a lever pivoted to a fixed fulcrum ina suitable position in relation to the cylinder and means connecting theplunger that is capable of exertin ga progressive increase of power orforce on the plunger as itis propelled inward in the cylinder, thuscompensating for and overcoming the increasing resistance encounteredwhen compressing air by pressure; third, to have a pump-cylinder of suchform and construction that it may be made sufficiently strong forhigh-pressure service, wholly or in part out of fragile or brittlematerial-such as glass, porcelain, or cast-iron-which it is verydesirable to do for many purposes on account of the cheapness andnon-corrosive character thereof, and, fourth, to have a plunger in whichthe form and arrangement of the parts adapt them to coperate, so as tomake the annular rim of the eXible packing effective as a valve for theinlet of air.

In the portion that appertains to the actuating mechanism the gist of myinvention consists in the location of the fixed fulcrum for the pivotedend of the lever, because that, being properly located and fixed inposition in proper relation to the cylinder, it becomes possible toeasily accomplish the second division of the object before stated bydiverse means of connecting the lever to the plunger. To render thisobvious, several different means for the purpose are illustrated anddescribed, the subjoined claims covering as a means an oscillating andreciprocating link. The other means shown are not particularized in theclaims, but are intended to be within their scope.

My invention further consists in the form, construction, and relativearrangement of the several parts and in combinations whereby the objectsheretofore stated are accomplished, al1 as hereinafter fullyset forth,and particularized in the subjoined claims.

In the accompanying drawings, forming part of this specification, Figurel is a central section on a plane parallel to the movement of the lever,showing the operating parts covered by subjoined claims in full lines.Fig. 2 is a central cross-section of the plunger enlarged to moreclearly show the details. Fig. 3 is a central section on the same planeas Fig. l, showing operating parts in full lines. Fig. 4 is a top Viewin full lines.

Like letters indicate like parts in all the figures.

The Wall of the cylinder A inclosing the vchamber A2 is formed taperingin section both inwardly and outwardly, so that its strength isgradually increased from the upper to the lower sections, as shown, thisbeing done to compensate for and resist the increasing eX- panding forceof the air caused when the plunger is depressed. It is also reinforcednear to, but above, the bottom A2of the chamber by an encircling flangea, which is also formed to serve as a base-plate and means for securingthe pump to a stand or other support. A boss o? is mounted on thisflange 0L and suitably joined tothe cylinder. Through this boss is anoutlet-passage a3, the outer end of which is closed by a removable pluga4. This outlet-passage serves as a means through which to blow out fromthe chamber A2 the surplus oil or other undesirable accumulations.Oommunicatingwith the passage a3 is another outlet-passage a5,formed andadapted to receive an outlet-valve c and other connections.

To the upper end of the cylinderA a standard B is rigidly secured in anysuitable manner, either With a top plate, as shown, or by directattachment lto the cylinder, as may be preferred. This standard B is soformed and adapted that it will firmly supportv in a fixed position thefulcrum-bearing B2 'at a point above the cylinder on a plane parallel toand within a distance from its axis not exceeding one-fourth thecylinders length and distant from the bottom of the cylinder-chamber A2not more than the distance found by measuring from the bottom of theplunger to the IOO center of the pivot articulating the link B4 to thelever B3 and thence to the center of the fulcrum B2 and not less thanthe same measurement would be less the thickness of the plunger. Theactuating-lever B3 is articulated to the fulcrum B2 in such manner as toallow it an oscillating movement of one hundred and eighty degrees. Alink B4, forming part of the means connecting the plunger to the fulcrumB2, is articulated to this lever B3 at a point distant from the centerof said fulcrum B2 of not less than half the length of the movementimparted to the plunger nor more than half the length of the cylinder A.The free end of this lever B3 may extend to a suitable length and therebe provided with a hand-grip B5. The link B4 may be duplex or single andof any suitable length, and its other end is articulated directly to aprojecting part of the plunger C or to a rod c', extending from theplunger. This `rod or stem c' is firmly attached to the `plunger andextends upward a suitable distance to pass through one or moreguide-bearings, as B6, located above the cylinder and adapted to guidethe rod so that the plunger will be carried concentrically within thecylinder and prevented from tilting. The top plate c of the plunger isin form a dat disk having the connecting means c2 extending from itsupper face and a screw-threaded stud c3 extending from its under face.An upward-,extending annular flange c4 may be provided on its peripheryand will serve as an additional means to-guide and steady the plungerand prevent it from tilting with the oscillation of the link B4. Theunder face of this top plate has an annular beveled port-ion c5, whichextends in- Ward about one-twelf th of its diameter. This beveledportion is pierced with a suitable number of holes c6 to admit air tothe cavity c7, formed between this beveled portion and the packing orflexible cup cs, which is held in position by the sleeve-nut c, clampingits central part to the under face of the top plate c. The periphery ofthe flexible cup is a downwardly-extending annular flange 010,

wedge-shaped in section, as shown, andthe bottom plate c, having aconical corresponding periphery, is fitted loosely within the flange cwand is likewise provided with a suitably-formed hole through its centeradapting it for a short sliding movement on `the sleeve-nut o9, the headportion of the nut c preventing it. from coming off. An annular rim cl2is raised on the upper side at the peripheral angle, which is suitablylarger in diameter than the inner diameter of the beveled portion c5 ofthe top plate c.

The operation of the plunger parts is as follows: When the top plate cis propelled in the cylinder inward, pressing before it the flexiblecup, the 'annular beveled portion c5 permits the flexible cup to yieldand bend backward, and the resistance of the air in the inclosedcylinder-chamber forces the bottom plate backward, causing its rim C12to press and bend the flexible cup backward, at the same time theconical periphery of the plate c11 acting in conjunction with thewedgeshaped flexible Bange c1" of the cup forces said flange outwardagainst the wall of the cylinder, thus securing a tight packing of theplunger foreach downwardmovement. As soon as the reverse movementcommences a reverse action takes place, the top plate releasing itspressure on the cup and receding from the bottom plate, carrying thecentral part of the cup with it, the friction of the flange 010retaining it for an instant until the bend of the cupisstraightenedandspace is allowed bcvtween the flange and the cylinder-wall for freepassage of `the incoming air. The inlet air-holes c6 through the topplatealso serve to admit oil for lubricating the `plunger-and packing.

Thecup-leatherof the plunger isa valve, as will be seen from thedescriptiomand `will expand and adapt itself tothe varying diameter ofthe cylinder, and this makes the insidetapering of .the cylinder a veryvaluable feature, because as the plunger expands itself at the beginningof the downward stroke, due to the compression of the air, `it is causedto pack tighter by reasonof the tapering of the cylinder as thecompression increases, while on ,the return stroke the plungercupleather resumes its contracted condition, thus allowinga space allaround it for air to freely pass below the plunger as 4the latter rises.

In operating the pump full stroke `thejoint articulating the lever tothe link moves `upward to a point about in line with theaxis of thecylinder and downward till the said joint very nearly reachesa point on`a right line mdrawn from .the center of the fulcrum to the center ofthe bottom of the cylinderchamber, when the plunger should contact withthe cylinder-bottom, thus effectively expelling all the air. It will beseen that in this movement-the lever and link acting as a toggle-jointincrease the force exerted on the plunger as `it encounters increasedresistance from the compression of the air.

Having thus described my invention, what I claim as new, and `desire tosecure by Letters Patent, is-

1. A pump comprising a cylinder and a plunger adapted to reciprocatetherein, a standard `secured to the cylinder and supporting a fulcrur11-bearing, an oscillating lever articulated to said fulcrum-bearingand a link connected to the plunger and articulated to said lever, thesaid point of articulation passing the axis-line of the cylinder on thedownward movement of the lever, the said fulcrumbearing being `supportedat a point above the cylinder on a plane parallel to and within adistance from its axis not exceeding onefourth the cylinders length, anddistant from the bottom of the cylinder not greater than the measurementfrom the bottom of the plunger to the center of the pivot joining saidlink to the operating-lever and thence to the IIO 'center of thefulcrum, and not less than the same measurement minus the thickness ofthe plunger.

2. In a pump, the combination with a cylinder and a plunger adapted toreciprocate therein, of a standard secured to said cylinder andsupporting fulcrum-bearing, as B2, a link, as B4, forming one part and alever, as B3, forming another part of the means connecting the plungerto the fulcrum B2, the said fulcrum B2 located at a point above thecylinder on a plane parallel to and within a distance from its axis notexceeding onefourth of the cylinders length, and distant from the bottomof the cylinder not greater than the measurement from the bottom of theplunger to the cent-er of the pivot for connecting rod or link B4 to theoperating-lever and thence to the center of the fulcrum, and not lessthan the same measurement minus the thickness of the plunger,substantially as set forth.

3. In a pump, in combination, a cylinder and a plunger adapted toreciprocate therein, a standard B rmly supporting in a fixed position afulcrum B2, an oscillating lever B3 articulated to fulcrum B2 and a linkB4 directly connected to the plunger within the cylinder and articulatedto lever B3, the said point of articulation passing the axis-line of thecylinder on the downward movement of the lever, the said fulcrum beingsupported at a point above the cylinder on a plane parallel to andwithin a distance from its axis not exceeding one-fourth the cylinderslength, and distant from the bottom of the cylinder not greater than themeasurement from the bottom ofthe plunger to the center of the pivotjoining link B4 to the operating-lever and thence to the center of thefulcrum, and not less than the saine measurement minus the thickness ofthe plunger, substantially as set forth.

4. In a pump, as an article of manufacture, a plunger consisting of thefollowing members, in combination a top plate as c having theprojections c2 and c2, the guidingflange c4 and the air-inlet holes c6;a exible cup-packing as c8 secured to the top plate by suitable means asc9 and having a peripheral wedge-shaped fiange as c10 and a bottom platehaving a conical periphery loosely fitted within said flange and adaptedto have a short sliding movement therein as described; these partscoperatin g together to make the ilange 040 act as an inlet-valve, inthe manner set forth.

5. Av cylinder for air-pumps tapered from its top to the lower portion,both inwardly and outwardly, making the cylinder smaller at the lowerportion than at the upper portion on the inside and thicker below thanat the top, as set forth.

6. A cylinder for air-pumpstapered from its top to the lower portionboth inwardly and outwardly making the cylinder smaller at the lowerportion than at the upper portion on the inside and thicker below thanat the top, and having an integral reinforcingflange a above its bottomand a bottom or ing-rod, a standard B firmly supporting in a fixedposition a fulcrum B2, an oscillating lever B3 articulated to thefulcrum B2 and a link B4 connected to the plunger within the cylinderand articulated to lever B3, the said point of articulation passing theaxis-line of the cylinder on the downward movement of the lever, thesaid fulcrum being supported at a point above the cylinder on a planeparallel to and within a distance from its axis not exceeding one-fourththe cylinders length,

and distant from the bottom of the cylinder JOHN N. MCLEAN. Witnesses:

I-I. E. STEINHILBER, EDMoND CoNoAR BROWN.

IOO

